How can you travel and not spend any money? You can just watch how others do it and shoot it on camera. Also, such videos are very well suited in order to decide which country, which continent you would like to go or fly to, and of course decide in advance where exactly to go, what to visit and so on.
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Everyone, for sure, even if he has never traveled outside his own city in his life, dreams of going somewhere, seeing the world, learning something new, enjoying vivid and memorable experiences. However, not everyone manages to travel as much as he wants. And in order to use it to the fullest every time you go on vacation, you need to choose in advance where to go and plan everything to the smallest detail.
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Walking through extreme and dangerous places on the globe excites the blood and makes you produce adrenaline, despite the fact that you are just watching it from the monitor screen. And if this topic is very close to you, then you can repeat their path by doing something that few people will do. Mountain biking in mountainous terrain, especially going down narrow paths at wild speed, skydiving from high-rise buildings, from rock cliffs and much more can be seen in travel videos.
Such videos can be of interest not only to an adult who wants to plan his vacation or just see how it is over the hill, but also for a child, this content may appeal to you. For a student, this can be an excellent educational material, and knowledge can be useful in mastering geography.
On the site, you have the opportunity to watch videos about travel, wandering around the interesting corners of our vast planet and at the same time watch all this without registration and absolutely free.
In terms of its versatility, information content and accessibility, ECG occupies one of the leading positions among instrumental examination methods. The basics of an ECG should be known to any health worker, and he should also be familiar with the technique of taking an ECG. After all, the result of the study depends on the ability to correctly apply electrodes and take a cardiogram. Proper ECG registration and adherence to the cardiogram removal algorithm is the first step towards making the correct diagnosis. Consider what the ECG technique includes, how preparation for the procedure should be carried out, and also what is the algorithm of actions.
The ECG technique is one of the practical skills that every student of a medical college and university owns. And if a student has not mastered this technique, he will not be with medicine “on you”. It is not without reason that this manipulation is carefully trained by the medical staff, because in emergency situations, recording an ECG and the ability to decipher a cardiogram can save a patient's life. At first glance, the ECG registration algorithm is extremely simple, but it has its own nuances, without knowledge of which the manipulation will not succeed.
The ECG registration scheme is as follows:
Let's take a closer look at these three points.
The patient takes a horizontal position on the couch with a bare torso, ankle and wrist joints free from clothing. After that, the medical worker proceeds to the application of electrodes. Limb electrodes in the form of plates with a screw are applied to the lower surface of the forearms and lower legs in a strictly established order in a clockwise direction. The electrode of each limb has its own color: Red - right arm, Yellow - left arm, Green - left leg, Black - right leg.
The chest electrodes are numbered, also colored and equipped with rubber suction cups. They are installed in a strictly defined place on the chest. Let us present the method of placing electrodes in the chest leads in the form of a diagram.
Location on the chest:
For better contact with the electrodes, it is advisable to degrease the skin with alcohol, it is recommended to shave the thick vegetation on the chest, moisten the skin with water or a special electrode gel (OKPD code 24.42.23.170). For better contact of the electrodes with the skin, you can place a damp cloth under the electrode plates. After the recording of the cardiogram is completed, the electrodes are removed from the patient's body, the remains of the gel are removed with a napkin, processed, disinfected, dried and placed in a special container. Such manipulations are carried out with reusable electrodes. They can be reused to record an ECG for another patient.
Electrodes for ECG are both reusable and disposable. Reusability is not the only classification of ECG electrodes. But there is no need to delve into the classification. Most often, in the functional diagnostics rooms of polyclinics, you can still see reusable electrodes on the ECG machine: limb, chest, with a screw and a clamp, a set of six pears. Reusable electrodes are economical, therefore they hold their positions in medicine.
Disposable electrodes have appeared relatively recently, their advantages include high accuracy of the transmitted signal, good fixation and stability during movements, and ease of use. Disposable electrodes are widely used in resuscitation and intensive care units, Holter monitoring, pediatrics, and surgery. The disadvantages of disposable electrodes include the impossibility of reuse.
There is also an ECG with a vacuum electrode application system, which is excellent for performing functional stress ECG tests. The electrodes in the system with a vacuum application fit very tightly and are well fixed, which allows you to freely take a cardiogram when the patient moves without losing the quality of the ECG signal. And if an electrode is suddenly disconnected, the system will let you know about it, because the ECG with the vacuum electrode application system is able to “control” the electrode disconnection.
After applying the electrodes and connecting them to the device, the leads are fixed and recorded on the paper recording tape of the cardiograph. In the case of taking an ECG, the patient's arms and legs will be "conductors" of the electrical activity of the heart, and an imaginary, conditional line between the arms and legs will be the leads. Thus, 3 standard leads are distinguished: I-forms the left and right arms, II - the left leg and right arm, III - the left leg and left arm.
First, with the help of limb electrodes, an ECG is recorded in standard leads, then in enhanced (aVR, aVL, aVF) from the limbs, and then in chest leads (V1-V6) using chest electrodes. The electrocardiograph has a scale and a lead switch, there are also buttons for voltage and tape advance speed (25 and 50 mm/s).
Recording devices use a special registration tape (for example, OKPD code 21.12.14.190), in appearance it resembles graph paper, has divisions, where each small cell is 1 mm, and one large cell is 5 mm. When the speed of such a tape is 50 mm / sec, one small cell is equal to 0.02 seconds, and one large cell is 0.1 seconds. If the patient is recording an ECG at rest, he should be explained that at the time of the immediate recording, one should not talk, strain, move, so that the recording results are not distorted.
Unfortunately, when recording an ECG, errors are not uncommon, both on the part of preparing patients for the procedure, and on the part of health workers when conducting the ECG registration algorithm. The most common errors leading to distortion of ECG results and the formation of artifacts are:
In order for the ECG results to be reliable and truthful, health workers need to clearly know the algorithm of actions when taking a cardiogram and the technique for conducting it, and patients should take a responsible approach to the study and follow all the rules and recommendations before conducting it. It should be noted that the ECG has no contraindications and side effects, which makes this research method even more attractive.
Electrocardiography is an accessible and informative procedure for diagnosing cardiac pathologies. The essence of the method is to fix electrical impulses, the occurrence of which is due to the rhythmic alternation of contractions and relaxations of the heart muscle over a certain time range.
An electrocardiograph (a special medical device) captures impulses coming from sensors mounted on the body and converts them into a graph. Such a graphic image is called an electrocardiogram, and is subject to further decoding by a cardiologist. Since ECG is done in a hospital setting and at home, there are stationary and portable cardiographs.
The main components of the device are:
Modern cardiographs have a high sensitivity to the bioelectrical activity of the heart muscle, and the accuracy of the transmission of impulse oscillations.
Removal of an electrocardiogram is carried out for the correct diagnosis of heart diseases. This procedure evaluates the following parameters:
An ECG is done in the following cases:
Graphic ECG registration is a broken line, sharp corners (teeth) of which are located above and below the horizontal line, on which time cycles are recorded. The teeth show the depth and frequency of rhythmic changes. The recovery phase between contractions of the heart muscle is indicated by the Latin T. Excitation or depolarization of the atria - R.
The correct location of the electrocardiograph sensors is the basis for taking an ECG
The recovery cycle of the distant ventricles of the heart is U. The state of excitation of the ventricles is displayed by Q, R, S teeth. Intermediate distances from one tooth to another, on the ECG are called segments (ST, QRST, TP). A fragment of the graph, a capturing segment and an adjacent tooth is called the interval of the impulse.
Leads or circuits that register the difference in potential indicators that the electrodes transmit are divided into three groups:
The records on the graph reflect the work of the heart in each lead, which allows you to analyze in more detail the work of all parts of the organ.
The algorithm of actions of medical specialists during the procedure:
The preparatory stage consists in the comfortable positioning of the patient horizontally on the back, on a medical couch. In case of difficulty in breathing, the instruction for the procedure allows a sitting position. Further, the skin areas where the electrodes are attached are treated with alcohol or another antiseptic, and a medical gel with a conductive property is applied to them. The ECG removal technique largely depends on the correct location of the electrodes on the subject's body.
According to the electrode application scheme, the patient's wrists, ankles and torso are involved in the process. For single-channel recording, one chest electrode is used, for multi-channel recording, six.
The ECG manual determines the exact location of the sensors on the human body. The electrodes are placed on the legs and arms in a clockwise direction, starting from the right upper limb. For convenience, the sensors are color-coded. Red for the right hand, yellow for the left hand, green for the left foot, black for the right foot.
The electrodes recording the chest leads are located between the ribs and in the line of the armpits as follows:
Experts are guided by these identification lines
With an ECG, the electrodes V4, V5 and V6 are applied at the same horizontal level. Applying electrodes in a different order is unacceptable. This affects the accuracy of the diagnosis. If you need a deep analysis of cardiac activity, it is customary to use the Slopak ECG technique. In this case, additional V7, V8, V9 leads are installed.
Before the planned ECG, the patient should exclude active physical activity, not be nervous. It is necessary to give up alcohol, and eat food no later than two hours before the examination. Do not take drugs that tonic or depress the work of the central nervous system (central nervous system), cardiac stimulants and sedatives. Breathing should be monitored during electrocardiography.
An even and calm breathing rhythm contributes to obtaining accurate data. Otherwise, the indications of the cardiogram may be biased. If an emergency medical care is needed, the cardiogram of the heart is done without preparation, and in the patient's state of health of any severity. People aged 40+ are advised to have an ECG done annually. In the presence of chronic heart disease, the frequency of the procedure is determined by the attending physician.
Graphic reflection on the cardiograph tape reflects the work of the heart. Sharp corners or teeth pointing up from the main horizontal line is positive, pointing down is negative. Electrocardiogram data is decoded according to the norms. For the adult population, the following indicators are taken as the basis:
The bases of cardiac disturbances on a millimeter graph are determined by counting the cells from one R wave to the next. Different distances between R-teeth indicate arrhythmias (changes in the frequency, regularity and sequence of heart contractions). The heart rate is below normal, due to the presence of bradycardia. A rapid heart rate diagnoses tachycardia. The correct heart rhythm is called sinus.
ECG chart showing the main parameters
Only a qualified specialist - a therapist or a cardiologist - can decode a graphic image on a tape or a photo of it. You should not engage in self-diagnosis of cardiac diseases.
The ability to properly take an ECG is reduced for the following reasons:
Some disadvantages of ECG:
Electrocardiography is an affordable and fast diagnostic method. Do not ignore discomfort in the chest area, and heart pain. You can undergo the procedure at any age in every district hospital.
An important skill for a nurse is correct EKG technique(electrocardiograms). Recall that electrocardiography is a technique for recording the electrical fields of the heart that arise in the course of its activity. as well as their receipt of their graphic image on paper or display. Electrocardiography is an informative and non-invasive method for studying the work of the heart - convenient and valuable for the patient and the attending physician.
Electrocardiogram is a graphic image in the form of a curve obtained during electrocardiography on paper or a display. ECG recording is carried out using devices - electrocardiographs. Any electrocardiograph has:
A nurse is allowed to work with an electrocardiograph only after training, best of all in the specialty "". ECG registration is carried out in a specially adapted and equipped room, as well as in the ward at the patient's bedside, at home, at the place of medical care, in an ambulance.
The ECG room must be kept away from any suspected sources of electrical interference. It is advisable to shield the couch: it is covered with a special blanket with a sewn-in grounded (!) metal mesh.
Immediately before the planned ECG registration, the patient should not eat, smoke, drink stimulating drinks (tea, coffee, "energy"), or physically load the body.
We fix in the necessary documentation the personal data of the patient, the number of the medical history, the date and time of the ECG.
Place the patient on the couch in the supine position. We degrease those areas of the skin where we will apply the electrodes - we wipe them with a napkin moistened with an isotonic sodium chloride solution (0.9%).
We apply electrodes: 4 plate electrodes - on the lower thirds of the inner surface of the legs and forearms, and on the chest - chest electrodes equipped with pear suction cups. For single-channel recording, 1 chest electrode is used, for multi-channel recording, several.
We attach wires of a certain color coming from the electrocardiograph to each electrode. Common labeling of electrocardiograph wires:
When registering an ECG in 6 chest leads in the presence of a six-channel electrocardiograph, the following tip markings are used:
Most often, an ECG is recorded in 12 leads:
Registration of standard limb leads is carried out when the electrodes are connected in pairs:
The electrodes are applied on the left arm, right arm and left leg (see the markings in the figure). The 4th electrode is applied to the right leg to connect to the ground wire.
Formation of three standard electrocardiographic leads from the extremities. Below - Einthoven's triangle, each side of which is the axis of one or another standard lead
Unipolar leads are characterized by the presence of only one active - positive - electrode, the negative electrode is indifferent and is a "combined Golberg electrode", which is formed when two limbs are connected through additional resistance.
Reinforced unipolar leads have the following designations:
Formation of three reinforced unipolar limb leads. Below - Einthoven's triangle and the location of the axes of three reinforced unipolar limb leads.
The chest leads in the ECG are unipolar. The active electrode is connected to the positive pole of the electrocardiograph, and the triple indifferent electrode united from the limbs is connected to the negative pole of the apparatus. The chest leads are usually denoted by the letter V:
When selecting the amplification of each channel of the electrocardiograph, it is necessary that a voltage of 1 mV causes a deviation of the galvanometer and the recording system of 10 mm. In the position of the switch leads "0" adjust the amplification of the device and register the calibration millivolt. If the amplitude of the teeth is too large (1 mV = 5 mm), the gain can be reduced, if it is small (1 mV = 15-20 mm), it can be increased.
An electrocardiogram is recorded with the patient breathing calmly. First - in I, II, III standard leads, then - in enhanced unipolar limb leads (aVR, aVL, aVF), then - in chest leads V1. V2, V3, V4, V5, V6. In each of the leads, at least 4 cardiac cycles should be recorded.
How can you conclude from the presented, with the necessary knowledge and skills EKG technique should not present any difficulties for the nurse. We suggest watching the video to consolidate what you have read
Here materials on independent production of the electrocardiograph and encephalograph with the minimum expenses of details and efforts are laid out and discussed. The presentation is carried out in the simplest possible language so that all these devices could be repeated by a novice radio amateur who has never even picked up a soldering iron in his life. In this regard, explanations of the principles of operation of certain devices from the point of view of a practitioner are also laid out here.
First of all, it should be noted that everything stated on the site has not been officially tested for electrical safety, so you use this information at your own peril and risk. The authors of the site disclaim any responsibility for any direct or indirect consequences, including for the body, which may result from the use of the devices discussed on the site.
Let's start with the simplest - how to make a cardiograph with your own hands. Further, we will develop this scheme to an encephalograph. So.
An electrocardiograph (or cardiograph) consists of two parts - analog and digital (see Fig. 1). The analog part is just an amplifier with a gain of about 1000 - it amplifies the time-varying potential difference on the human body (which is, in our case, in fact, an electrocardiogram) by about 1000 times. Next, the amplified signal goes to the digital part, where the signal is digitized (see about what digitization is) and fed digitally to a computer (we have a digital signal sent via the bluetooth radio channel - see below).
Fig.1
As a result, the computer, using a special program, decodes the digital signal received from the digital part (we implemented it on the basis of the Arduino board - see below) and draws an electrocardiogram (ECG) graph on the monitor screen.
Digital part of the circuit
To simplify the manufacture of the device, as a digital part, we take an Arduno-type board (Arduino) with bluetooth on board. For example, you can take Iteaduino BT v1.1 as such a board. The price of this device is about 1200 rubles. (see, for example,). At the same time, the feature of our system is that the digital signal will be transmitted to the computer Necessarily via the bluetooth channel i.e. by radio channel. Thus, there will be no galvanic connection between the computer and our device, and hence the patient's body. This ensures that dangerous voltages, for example, from a computer case, which can reach up to 110V, cannot reach the patient's body (see, for example,). Therefore, we emphasize once again that for the purposes of electrical safety, when the device is connected to the patient's body, a signal must be transmitted to the computer only by bluetooth, this opportunity is provided by the board we have chosen. Thus, the patient's body will be connected to a device powered by 9V and in no way connected to power sources with a dangerous voltage level.
As a result, the development of the digital part comes down only to setting up the bluetooth channel of our board, “uploading” the corresponding program (sketch) onto the board - this program “explains” Arduino from which connector the board will read the signal (we have from connector A0) in order to digitize and in which format, this digitized signal will be transmitted to the computer. You will also need a computer program that reads and decrypts the data supplied by the board to the computer - to one of its software com ports. As a result, in hardware, the digital part of the project looks like this: 
fig.2
It is also advisable to connect its analog part to the Arduino through zener diodes and a Schottky diode - like this: 
fig.3
Here is a Schottky diode (BAT85) and zener diodes (BZX55C2V4) - to protect against reverse polarity and exceeding the 5V signal at the Arduino input. They are needed at least at the stage of setting up the circuit, when you can confuse plus with minus, etc. and eventually burn a fairly expensive Arduino. Also, these diodes in this project are important not only from this point of view (see below). In short, the meaning of this protection is as follows. The Schottky diode (BAT85), if the analog part of the circuit tries to apply a positive voltage between A0 and GND, has a resistance close to infinity, then this very positive voltage (positive potential difference) from the analog part is safely supplied to A0 and GND. If the analog part tries to somehow apply a negative voltage to A0 and GND, then the Schottky diode turns into a short circuit - a resistor with a resistance close to zero. As a result, all the current flows through the Schottky diode, and the voltage between A0 and GND goes to zero. Two zener diodes connected in series (BZX55C2V4) in this circuit, if a positive voltage is applied to them, like the Schottky diode, have a resistance close to infinity, but only if this voltage is within 4.5V. If the analog part of the circuit tries to somehow apply a voltage greater than 4.5V to A0 and GND, then these two diodes also turn into low resistance resistors - almost all the current flows through them and thus the voltage between points A0 and GND does not exceed 4.5 IN. You can also see more about protective diodes. About setting up bluetooth, "filling" sketches in Arduino and different ways to view the received data on a computer, see. Thus, what would take a novice radio amateur to manufacture and configure a digital part of at least 1-2 months, we, thanks to the use of Arduino, take a maximum of 3-7 days.
Analog part of the circuit
Now let's move on to the analog part of our circuit. The analog part is under construction
Comments
Maria
09/09/13 16:20
Hello! Thank you very much for the information you share here. I'm going to make an electroencephalograph and I can't find the Iteaduino BT V1.1 (ATmega 328) anywhere. Please tell me if it is possible to use Iteaduino BT V1.0 (ATmega 328) or other microcontrollers instead. And, if possible, what or what it is fraught with. Thank you in advance!
Konstantin
09/09/13 18:17
Hello Maria! I myself worked only with version v1.1, however, if you look at the latest datasheet for Iteaduino BT V1.0 ATmega 328 (the link to it is: ftp://imall.iteadstudio.com/IM120411006_Iteaduino_BT/Documents/DS_IM120411006_Iteaduino_BT.pdf - this link also given here in the Arduino setup section), then at the very end of this datasheet it is given how Iteaduino BT v1.1 differs from Iteaduino BT v1.0. It says: Fix some description bug. Thus, as I understand it, all the difference comes down to correcting errors in the description of the board in the datasheet, and these versions seem to work the same way. By the way, on this page there is the following link to the online store: http://devicter.ru/goods/Iteaduino-BT-with-ATMega328P and so, iteaduino BT V1.1 ATmega 328 is sold there.
Maria
10/09/13 15:11
Thanks a lot! You helped me a lot! If I develop something worthwhile for science on the basis of your EEG, then I will owe it to you))
Maria
10/09/13 16:00
I have already seen the site that you recommended to me, but I live in Moscow, and the goods presented there are from Novorisibsk!)) Sorry, one more question: which TL431 is better to choose: http://www.chipdip.ru/product/ tl431acd/ http://www.chipdip.ru/product/tl431acdbzr/ http://www.chipdip.ru/product/tl431aclp-ti/ http://www.chipdip.ru/product/tl431clp/ http:// www.chipdip.ru/product/tl431ilp/ http://www.chipdip.ru/product/tl431cpk/
Konstantin
10/09/13 20:37
It's nice, of course, that the information on this site is useful and in demand. Especially for science :-). As for the TL431, if you assemble everything from the beginning on the basis of a solderless mounting board (by the way, I recommend starting that way), then it will no doubt be more convenient in the TO92 case - for example, this one: http://www.chipdip.ru/product/ tl431ilp/ Well, if you are going to solder right away, then I can say that planar elements (where the body type is SO, SOT in your links) are rather small things (you can see the dimensions in the datasheet) and solder them without the appropriate experience, for example , with an ordinary soldering iron, is quite difficult (although if you read the Internet, practice, then this is not such a big problem). Usually this is soldered using a soldering station. So here I recommend it in the TO92 package.
Sergey
24/01/14 18:03
And where to start the \"O\" cable? Bury in the ground?
Konstantin
24/01/14 20:54
Here you duplicated your question - there I answered.
earth_man
30/04/15 17:20
Hello Konstantin, thank you very much for the site. I have never dealt with electronics before and my knowledge in this area tends to zero. Tell me, how possible is it to create what you propose in your instructions with zero knowledge on the topic? What would you recommend to read in order to enter the topic more gently and without stress and do an ECG, EEG yourself?
Konstantin
30/04/15 18:44
Hello earth_man! In principle, it is enough to be able to measure voltage and current, within the school to know how the current flows, to know Ohm's law, it is also advisable to read on this site about amplifiers, about digitization and matching (I posted this here so that beginners have the necessary minimum , which is sufficient to repeat these devices). And of course, you will have to arm yourself with patience and start assembling the circuit not all at once, but step by step: we assembled the power supply, checked whether it gives out what we need, then we assemble the repeater, check if it works as it should, etc. This allows you to not only minimize stress, but even get positive emotions as you move from victory to victory. This element of the circuit has earned - a victory and at the same time the realization that now you, not only in theory, but also in practice, know what needs to be done to make the same repeater work or how to connect the amplifier correctly, which means that if necessary, you can use this knowledge without only for ECG or EEG, but also for the implementation of some of their schemes, and so on. And of course, it is desirable to do all this on the basis of a solderless mounting board - this is very convenient, especially for beginners.
earth_man
30/04/15 21:54
Thanks a lot for the inspiring answer. It will be necessary to read physics for the eighth grade :), I would like to better understand the theoretical part before starting any manipulations.
Rinat
16/01/16 1:34
Iteaduino BT v1.1. Online store: http://devicter.ru/goods/Iteaduino-BT-with-ATMega328P I couldn't find it. Maybe under a different estate, but not in the picture either.
Konstantin
16/01/16 9:35
Hello Rinat! Yes, I looked, I also didn’t find this board from them now, although I used to buy it from them. Here you either have to look for this board elsewhere, or you can buy a standard Arduino, an HC-05 bluetooth module and connect it to the board. The Internet has a way to do it. You can also buy Iteaduino IBoard V1.1 (ATmega 328) (http://devicter.ru/goods/Iteaduino-Iboard) in the same store http://devicter.ru/ and a bluetooth or even a wi-fi module of the series XBee (this board just supports them). XBee series in this store here: http://devicter.ru/catalog/BeeSeries
Rinat
16/01/16 20:53
Thanks Konstantin. I'll try to look for teaduino BT v1.1. Since, the scheme will have to be changed, and I am the first to climb into such a jungle. I have long wanted to have an encephalograph.
Anastasia
29/09/18 0:52
Hello Konstantin. Please advise where in Ukraine to find the Iteaduino BT V1.1 ATmega 328 board.
Konstantin
29/09/18 12:44
Hello Anastasia! I can probably only advise, if it is not possible to buy such a board, then you can buy, for example, the HC-05 bluetooth module for an ordinary arduino and make them friends - there are articles on the Internet about this. You can generally use a wifi module instead of a bluetooth module - everything is also very easy to connect there. Instead of bluetooth, you can use various arduino radio modules like nRF24L01 or something similar. In general, there are a lot of options for how to transmit a signal from an arduino over a radio channel - all these various radio modules usually cost a penny and are very easy to connect to an arduino.
